530 5.7.1 client was not authenticated max mail

A classic error!

The error message "530 5.7.1 Client was not authenticated" typically indicates that the mail server (SMTP) is refusing to accept the email because the client (your email client or script) is not authenticated.

Here are a few possible reasons for this error:

  1. No authentication credentials: The mail server requires authentication (e.g., username and password) to send emails, but your client is not providing the necessary credentials.
  2. Incorrect authentication credentials: The credentials you're providing are incorrect, so the mail server is refusing to authenticate your client.
  3. Authentication method not supported: The mail server only supports certain authentication methods (e.g., SMTP-AUTH, PLAIN, or LOGIN), but your client is using a different method.
  4. Firewall or network issues: There might be a firewall or network issue preventing your client from connecting to the mail server.

To resolve this issue, you can try the following:

  1. Check your authentication credentials: Verify that your username and password are correct and match the settings on your mail server.
  2. Use the correct authentication method: Ensure that your client is using the same authentication method as the mail server (e.g., SMTP-AUTH, PLAIN, or LOGIN).
  3. Configure your client to use authentication: If your client doesn't support authentication, you may need to use a different client or configure your existing client to use authentication.
  4. Check your firewall and network settings: Ensure that your firewall and network settings are not blocking the connection to the mail server.
  5. Contact your mail server administrator: If you're still having trouble, contact your mail server administrator to see if there are any specific settings or configurations required for your client.

Remember to always follow best practices for email authentication and security to prevent spam and other issues.